Chemistry terminology · MLC-0109

Chemistry terms: D (730)

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• DispositionThe overall process describing the fate of a substance within a living organism, encompassing its absorption...
• DisproportionationA chemical reaction in which a single substance acts as both an oxidizing and a reducing agent, resulting in...
• DisruptionA teratogenic effect involving the breakdown of a normally formed organ or tissue, leading to a structural...
• DisruptorA chemical species that interferes with the ordered arrangement of mesogenic units in a liquid crystalline...
• DissipationThe irreversible process by which a substance is dispersed, diluted, or transformed within a medium, leading...
• DissociationThe process by which a molecule or an ionic compound separates into smaller molecules, atoms, or ions...
• Dissociation energyThe energy required to break a specific chemical bond in a molecule, resulting in the separation of the...
• Dissociative adsorptionThe process by which a molecule, upon interacting with a surface, breaks apart into two or more atomic or...
• Dissociative electron captureAn ionization mechanism in which a molecule captures a low-energy electron to form a transient negative ion...
• Dissociative ionizationAn ionization process in which a molecule gains or loses an electron, and simultaneously breaks into two or...
• Dissociative surface reactionA chemical reaction occurring on a surface where at least one reactant molecule undergoes bond cleavage upon...
• DissolutionThe process by which a solute disperses into a solvent to form a homogeneous solution. This involves the...
• Dissolution inhibitorA compound added to a polymer resist formulation that reduces the dissolution rate of the unexposed polymer...
• Dissolution promoterA compound added to a photoresist formulation that increases the dissolution rate of the exposed or reacted...
• Dissolution rateThe speed at which a solid material, such as a polymer photoresist, dissolves when exposed to a solvent or...
• Dissolved organic carbonThe fraction of organic carbon in a water sample that passes through a filter, operationally defined by a...
• Dissolved organic matterA complex and heterogeneous mixture of organic compounds found in water that have passed through a filter...
• Dissolved oxygen contentThe concentration of molecular oxygen (O2) gas that is dissolved in a given volume of water. This parameter...
• Dissymmetry of scatteringA measure of the asymmetry in the angular distribution of scattered light, particularly from large particles...
• DistalDescribing a position lying farther from the trunk, or from the point where a structure begins or is...
• Distonic radical cationA radical cation in which the positive charge and the radical center are located at different, non-adjacent...
• Distortion interaction modelA conceptual framework used to analyze reaction barriers by partitioning the activation energy into two...
• Distortionless enhancement by polarization transferA nuclear magnetic resonance (NMR) spectroscopy pulse sequence designed to enhance the signals of carbon-13...
• DistribuendThe specific chemical species being distributed between two immiscible or partially miscible phases. This...
• DistributionThe apportionment of a solute, the distribuend, between two immiscible or partially miscible liquid phases in...
• Distribution constantThe ratio of the concentration of a solute in the stationary phase to its concentration in the mobile phase...
• Distribution constant calibrationA calibration approach for extraction carried out close to equilibrium, in which the analyte concentration in...
• Distribution constant (exclusion)A parameter in size-exclusion chromatography that quantifies the extent to which a solute can penetrate the...
• Distribution functionA mathematical function describing how the molecules in a polymer sample are distributed with respect to a...
• Distribution isothermA curve or function giving the stationary-phase concentration of an analyte in terms of its mobile-phase...
• Distribution ratioThe quotient of the summed concentration of all forms of a solute in one phase and its summed concentration...
• Distribution volumeA theoretical volume that relates the total amount of a drug in the body to its concentration in the plasma...
• DisturbanceAn event or force that causes a change in an ecological system, altering its structure, composition, or...
• Disyndiotactic polymerA polymer in which each monomeric unit contains two stereocenters, and the configurations of these...
• Ditactic polymerA polymer chain possessing two stereochemically distinct sites within each repeating monomer unit, leading to...
• DiterpenoidsTerpenoids having a skeleton of 20 carbon atoms, formally built from four isoprene units, with...
• Ditopic receptorA molecule or supramolecular assembly that possesses two distinct binding sites capable of simultaneously...
• DiuresisThe physiological process of increased urine production by the kidneys, resulting in the excretion of excess...
• DiureticA substance, agent, or drug that promotes diuresis, leading to an increased excretion of urine. These agents...
• Diurnal variationThe regular pattern of change or fluctuation in a physical or chemical parameter that occurs over a 24-hour...
• DiversityThe structural dissimilarity among molecules within a collection, such as a chemical library used for drug...
• Diversity geneA specific gene segment, also known as a D gene, that contributes to the variability of immunoglobulin and...
• Diversity indexA quantitative measure that reflects the variety and relative abundance of different species or types within...
• Diversity-oriented synthesisA synthetic chemistry strategy that aims to produce a collection of structurally different small molecules...
• DiverticulumA blind-ending pouch or sac that branches out from a hollow organ, tube, or cavity within the body. These...
• Divided granuleA granulated dosage form in which each dose is packaged separately, for example in a sachet or a gelatin...
• Divided powderA pharmaceutical preparation consisting of a single dose of a powdered drug mixture, individually wrapped in...
• Divided spinning cellA shallow dish-shaped sample holder for Raman spectroscopy that a vertical wall splits into two halves, one...
• Dividing surfaceA conceptual surface used in transition state theory to separate reactants from products along a reaction...
• DM-interferenceAn interference effect observed in analytical chemistry where a component in the sample matrix directly...
• DNA probeA single-stranded segment of deoxyribonucleic acid (DNA) or ribonucleic acid (RNA) that is labeled with a...
• DNA vaccinationA method of immunization that involves introducing a plasmid DNA encoding a specific antigen into a host...
• Dobson unitA unit of measurement used to describe the total amount of ozone in a vertical column of the Earth's...
• DockingA computational method used to predict the preferred orientation of one molecule (the ligand) when bound to...
• Docking studiesComputational investigations that predict the binding modes and affinities of small molecules (ligands) to...
• Doctor bladingA technique for creating thin films by spreading a liquid or paste material onto a substrate using a blade or...
• Dodecahedro-A structural descriptor in inorganic cluster nomenclature that denotes eight atoms arranged at the vertices...
• DolicholsA class of long-chain polyisoprenoid alcohols that are found in the membranes of eukaryotic cells. These...
• DomainA distinct, structurally compact, and independently folding region within a single polypeptide chain of a...
• DominantDescribing an allele or a trait that is expressed phenotypically even when only one copy of the allele is...
• Dominant half lifeThe half-life of a substance in a particular organ or compartment, chosen because it approximately defines...
• Dominant hemisphereThe cerebral hemisphere that is primarily responsible for certain specialized functions, particularly...
• Dominant lamellaeThe population of crystalline lamellae that forms during the primary crystallization stage of a polymer from...
• Dominant lethal mutationA genetic alteration in a germ cell that, when transmitted to the zygote, results in the death of the embryo...
• Domoic acidA neurotoxic amino acid produced by certain marine diatoms, particularly those in the genus Pseudo-nitzschia...
• DonicityA quantitative measure of the Lewis basicity of a solvent, representing its ability to donate an electron...
• Donnan emfThe electromotive force (emf) that develops across a semipermeable membrane separating two electrolyte...
• Donnan equilibriumA state of equilibrium achieved across a semipermeable membrane that separates two solutions, one of which...
• Donnan exclusionThe phenomenon where the concentration of mobile ions inside a charged membrane or gel differs from their...
• Donor numberAn empirical parameter that quantifies the Lewis basicity or electron-donating ability of a solvent. It is...
• Donor phaseThe phase in a separation process, such as liquid-liquid extraction, that initially contains the analyte of...
• DopamineA catecholamine neurotransmitter in the brain that regulates motor control, motivation, reward, and cognitive...
• DopantA substance added in small quantities to a polymer to modify its electrical, optical, or other physical...
• DopingThe deliberate introduction of small quantities of a foreign substance, known as a dopant, into a pure solid...
• Doping (p- and n-type), see Doping
• Doppler broadeningThe widening of spectral lines caused by the random thermal motion of atoms or molecules emitting or...
• Dormant polymer chainA polymer chain that has temporarily ceased growing but retains its ability to reactivate and continue...
• Dormant speciesA temporarily deactivated chain carrier, that is, a polymer chain that has stopped growing but can be...
• Dorsal rootA bundle of sensory nerve fibers that carries afferent signals from the periphery into the spinal cord. These...
• Dorsal root ganglionA cluster of sensory neuron cell bodies located along the dorsal root of a spinal nerve. These ganglia are...
• DosageThe product of an airborne pollutant's concentration and the duration of exposure, such as parts per million...
• Dosage formThe physical form in which a drug is manufactured and administered to a patient, designed to deliver the...
• Dosage regimenThe prescribed schedule for administering a drug, including the dose, frequency, and duration of treatment...
• DoseThe quantity of a substance or radiation administered to, or absorbed by, an organism or system. In...
• Dose equivalentA quantity for comparing the biological effect of different ionizing radiations, obtained by multiplying the...
• Dose-effectThe relationship between the dose of a substance and the magnitude of a specific biological or toxicological...
• Dose-effect curveA graphical representation plotting the magnitude of a specific biological effect against the administered...
• Dose-effect relationshipThe correlation between the amount of a substance administered to an organism and the resulting biological...
• Dose-response and dose-effect relationshipsTwo related concepts that characterize the connection between the amount of a substance administered and the...
• Dose-response curveA graphical representation showing the relationship between the dose of a substance and the proportion of a...
• Dose-response relationshipThe association between the administered dose of a substance and the proportion of an exposed population that...
• Double escape peakA peak observed in gamma-ray spectra that occurs at an energy 1.022 MeV below the full-energy peak of an...
• Double exposureA lithographic technique where a resist-coated substrate is exposed to radiation twice, either with different...
• Double helixA structural motif in which two helical strands are wound around a common axis. In biology, this describes...
• Double injectionThe simultaneous entry of both electrons and holes into a device or sample, normally from two different...
• Double patterningA lithographic technique that creates fine features by splitting a single design layer into two or more...
• Double pulsed-field gradient spin-echo excitationAn NMR pulse sequence that places two pulsed-field-gradient spin echoes in series, each containing a...
• Double resonanceA spectroscopic technique where two different electromagnetic fields are simultaneously applied to a sample...
• Double-beam spectrometerAn instrument that splits a beam of electromagnetic radiation into two separate paths, a sample beam and a...
• Double-focusing mass spectrographAn instrument that combines an electric sector and a magnetic sector so that ions diverging in direction and...
• Double-focusing mass spectrometerA mass spectrometer that employs a combination of an electric field and a magnetic field to focus ions...
• Double-labelled proteinA protein in which essentially every nitrogen is 15N and every carbon is 13C, usually produced by expression...
• Double-layer currentThe non-faradaic current that flows when the potential of an electrode changes and the ions at its surface...
• Double-negative cellA type of T lymphocyte precursor cell found in the thymus that lacks both the CD4 and CD8 co-receptor...
• Double-positive cellA type of T lymphocyte precursor cell found in the thymus that simultaneously expresses both the CD4 and CD8...
• Double-pulse laser-induced breakdown spectroscopyA variant of laser-induced breakdown spectroscopy (LIBS) that uses two sequential laser pulses to generate...
• Double-quantum filtered correlation spectroscopyA nuclear magnetic resonance (NMR) technique that selectively detects signals arising from coupled spin...
• Double-strand chainA polymer chain composed of two linear sequences of constitutional units that are interconnected at regular...
• Double-strand copolymerA copolymer whose macromolecule consists of two linear sequences of constitutional units, each of which is a...
• Double-strand macromoleculeA macromolecule characterized by two linear sequences of constitutional units that are interconnected at...
• Double-strand polymerA polymer whose macromolecules have two parallel strands tied together, either by regular rungs as in ladder...
• Doublet stateAn electronic state of an atom or molecule characterized by a total spin angular momentum quantum number of...
• Double-wavelength spectroscopyA spectroscopic method that measures absorbance or transmittance at two different wavelengths simultaneously...
• Doubling timeThe period of time required for a quantity, such as a microbial cell population or the concentration of a...
• DownconversionThe process where a high-energy photon is absorbed by a material, and its energy is subsequently re-emitted...
• DownstreamThe region or side of a membrane that is located after the membrane in the direction of the permeate flow...
• Down-timeThe period during which an automated analytical instrument or system is not available for its intended...
• DownwashThe downward movement of a plume of smoke or other effluent immediately after exiting a stack, caused by...
• DP, DQ, and DR moleculesSpecific types of major histocompatibility complex (MHC) class II molecules found on the surface of...
• Drainage basinAn area of land where all surface water from rain, melting snow, or ice converges to a single outlet, such as...
• Draining lymph nodeA regional lymph node that receives lymphatic fluid and antigens from a specific anatomical area or tissue...
• Draize testA controversial acute toxicity test developed in 1944 to assess the irritancy of substances on the skin or...
• DriftThe slow, unidirectional change in the baseline or output signal of an analytical instrument over a period of...
• Drift currentThe electric current that arises from the movement of charge carriers within a material under the influence...
• Drift tubeA component in certain mass spectrometry instruments, particularly ion mobility spectrometers, consisting of...
• Drift velocityThe average velocity attained by charge carriers, such as electrons or holes, in a material under the...
• Driving forceThe thermodynamic potential that causes a chemical reaction or physical process to proceed spontaneously. It...
• Drop timeThe interval between the detachment of successive mercury drops from the capillary tip of a dropping mercury...
• DropletA small liquid particle suspended in or falling through a gas, formed by condensation of vapor or by breakup...
• Dropping mercury electrodeA working electrode in electroanalytical chemistry that consists of a continuous stream of small, discrete...
• Drude-Nernst equationAn equation that describes the relationship between the volume electrostriction of a solvent and the change...
• DrugA substance, other than food, intended to affect the structure or function of the body, or to be used in the...
• Drug carrierA material or system designed to encapsulate, transport, and deliver a pharmacologically active substance to...
• Drug cocktailA combination of two or more pharmaceutical agents administered concurrently to a patient. This approach is...
• Drug deliveryThe methods, formulations, and systems for transporting a pharmaceutical compound to a specific location...
• Drug delivery systemA formulation or device that transports a pharmaceutical agent to its site of action within the body. These...
• Drug designThe rational approach to discovering new therapeutic compounds by understanding the structure and function of...
• Drug distributionThe reversible movement of a drug from the systemic circulation into the tissues and organs of the body. This...
• Drug metabolizing enzymeAn enzyme that modifies xenobiotics, including drugs, through biochemical reactions, altering their activity...
• Drug repurposingThe process of identifying new therapeutic uses for existing drugs that have already been approved for other...
• Drug safetyThe assessment and management of risks associated with the use of pharmaceutical products. This field...
• Drug-eluting stentA medical device, typically a small mesh tube, implanted into a narrowed artery to keep it open and prevent...
• DruggabilityThe likelihood that a given biological target can be modulated by a small molecule drug with acceptable...
• Drug-induced autoimmunityAn immune response where the body's own tissues are attacked due to exposure to a pharmaceutical agent. This...
• Drug-induced lupusAn autoimmune disorder, similar to systemic lupus erythematosus, that is caused by exposure to certain...
• Drug-likenessA qualitative concept used in drug discovery to assess how closely a chemical compound resembles known oral...
• Drug-specific T cellA T lymphocyte that recognizes and responds to a specific drug or drug metabolite, often leading to an immune...
• Dry bulb temperatureThe temperature of air measured by a standard thermometer that is exposed to the air but shielded from...
• Dry depositionA process in which a material is deposited onto a substrate from the vapor phase without the use of a liquid...
• Dry developmentA lithographic process where the exposed resist material is selectively removed using a dry etching...
• Dry etchingA process that removes material from a substrate using reactive gases or plasma, rather than liquid...
• Dry-etch resistanceThe ability of a polymer resist material to withstand erosion during a dry-etching process, which uses...
• Drying agentA substance used to remove water or moisture from another substance or from the surrounding environment...
• Drying control chemical additiveA co-solvent added to a sol so that the resulting gel can be dried quickly without cracking. It works by...
• Drying gasAn inert gas, such as nitrogen, introduced into an atmospheric pressure ionization source to aid in...
• Dual binding siteA characteristic of a biological macromolecule, such as an enzyme or receptor, that possesses two distinct...
• Dual fluorescenceThe emission of light from two distinct excited states of a single fluorophore, resulting in two separate...
• Dual substituent-parameter equationA linear free-energy relationship that separates the electronic effects of substituents into inductive (or...
• Dual viewing modeA configuration in inductively coupled plasma (ICP) optical emission spectrometry where the plasma can be...
• Dual-beam profilingA secondary-ion mass spectrometry mode for sputter depth profiling that uses two ion guns. In time-of-flight...
• Dual-mode photochromismPhotochromism in complex systems that can be triggered by either of two different external stimuli, for...
• Dual-tone resistA photoresist material that can function as either a positive-tone or negative-tone resist depending on the...
• DuctA tubular structure within the body that transports secretions from a gland or organ to another location...
• Ductus arteriosisA short vessel in the fetal circulation that carries blood from the pulmonary artery to the descending aorta...
• Dummy factorA factor entered in an experimental design as a placeholder because it is known not to influence the measured...
• Dung fly testA bioassay that tests the toxicity of a substance, such as a veterinary drug residue, by mixing it into...
• DuodenumThe first and shortest segment of the small intestine, immediately following the stomach and leading into the...
• Duplicate portion sampling methodA technique used in dietary exposure assessment where individuals collect identical portions of all food and...
• Duplicate samplesTwo separate samples taken from the same source under identical conditions, intended to be indistinguishable...
• Dura materThe outermost and toughest of the three meninges covering the brain and spinal cord, a thick fibrous membrane...
• DurabilityThe capacity of a material or product to maintain its intended function and properties over a specified...
• DustSmall, dry solid particles projected into the atmosphere by natural forces, such as wind or volcanic...
• Dust collectorA system used to enhance air quality by collecting dust and other impurities from air or gas. It operates by...
• Dust fallThe deposition of particulate matter from the atmosphere onto a surface, primarily due to gravitational...
• Dusting powderA finely divided solid preparation intended for external application to the skin, typically for its...
• Dwell timeThe time interval between successive sampled data points in a digitised spectroscopic signal, or the time a...
• Dye laserA type of laser that uses an organic dye solution as its gain medium, capable of producing coherent light...
• DynamerA polymer or macromolecular assembly characterized by its ability to undergo reversible changes in its...
• Dynamic bioaccessibilityA way of estimating how much of an analyte becomes bioaccessible, in which fresh simulated digestive fluid...
• Dynamic emittance matchingA technique used in ion beam analysis, particularly with raster scanning, to maintain optimal transmission of...
• Dynamic energy budget theoryA theoretical framework that describes the acquisition, allocation, and use of energy by individual organisms...
• Dynamic exclusionA data acquisition strategy employed in tandem mass spectrometry (MS/MS) where previously fragmented ions are...
• Dynamic extractionAn extraction method where fresh solvent or extracting phase is continuously passed through or over the...
• Dynamic fields mass spectrometerA mass spectrometer that uses time-varying electric or magnetic fields to separate ions based on their...
• Dynamic headspace analysisA technique for analyzing volatile compounds in a sample by continuously sweeping an inert gas through the...
• Dynamic light scatteringA technique used to measure the size distribution of particles or macromolecules in a solution or suspension...
• Dynamic mechanical analyserAn instrument that measures the viscoelastic properties of materials by applying an oscillating force or...
• Dynamic mechanical analysisA thermal analysis technique that measures the viscoelastic properties of materials as a function of...
• Dynamic membrane formationThe in-situ creation of a selective layer on a porous support, typically by the deposition of colloidal...
• Dynamic NMRA nuclear magnetic resonance (NMR) spectroscopy technique that analyzes the temperature-dependent changes in...
• Dynamic photoadsorption processA process on an illuminated photocatalyst in which photoadsorption of a species and its photodesorption occur...
• Dynamic rangeThe span between the smallest and largest values that an instrument or system can accurately measure. It...
• Dynamic reaction pathA trajectory in phase space that describes the time-evolution of a chemical reaction, considering the motion...
• Dynamic secondary-ion mass spectrometryA surface analysis technique that uses a focused primary ion beam to continuously sputter material from a...
• Dynamic spectrumA representation of spectral data that changes over time or with an external perturbation, such as...
• Dynamic stability hypothesisThe proposition that longer food chains are less stable than shorter ones. It posits that fluctuations at...
• Dynamic structure factorA function that describes the collective dynamics of particles in a system, providing information about both...
• Dynamic surface tensionThe surface tension of a liquid measured at a non-equilibrium state, where the surface area is changing or...
• Dynamic techniqueAn experimental method in thermal analysis where a property of a material is measured while the temperature...
• Dynamic thermomechanometryA thermal analysis technique that measures the mechanical properties of a material as a function of...
• Dynamic time warpingAn algorithm used to find an optimal alignment between two time series that may vary in speed or timing. This...
• Dynamic viscometerAn apparatus that drives a strip-shaped sample with a sinusoidal displacement at a frequency away from...
• Dynamic viscosityA measure of a fluid's resistance to shear flow, representing the internal friction between adjacent layers...
• Dynamically fragile communityAn ecological community that exhibits a high sensitivity to disturbances, leading to rapid and substantial...
• Dynamically robust communityAn ecological community that maintains its structure and function despite environmental disturbances or...
• Dynamic-load thermomechanical analysisA thermomechanical analysis technique where a material is subjected to a periodically varying mechanical load...
• DyneA unit of force in the centimeter-gram-second (CGS) system of units. It is defined as the force required to...
• DyneinA family of motor proteins that move along microtubules within cells. Dyneins convert the chemical energy...
• DynorphinA class of endogenous opioid peptides that function as neurotransmitters in the brain. These peptides are...
• Dyotropic rearrangementA pericyclic reaction in which two sigma bonds migrate simultaneously and intramolecularly, in one concerted...
• DypnonesUnsaturated ketones formally derived from the self-condensation of two molecules of an aryl methyl ketone...
• DysaphiaA neurological condition characterized by an impaired sense of touch or tactile discrimination. Individuals...
• DysarthriaA motor speech disorder resulting from neurological injury to the motor component of the central or...
• DysesthesiaAn abnormal, unpleasant sensation experienced in response to a normal stimulus, or even spontaneously...
• DysfunctionAn impairment or abnormality in the function of an organ, system, or biological process. This deviation from...
• DysgenesisAbnormal development of an organ or tissue during embryonic or fetal growth, resulting in its incomplete...
• DysgonesisImpaired development of the gonads, the primary reproductive organs, during embryonic or fetal stages. This...
• DysgraphiaA neurological disorder characterized by difficulties in writing, which can manifest as problems with...
• DyskinesiaA category of involuntary, erratic, and uncontrolled movements of the body, often affecting the limbs, trunk...
• DyslexiaA specific learning disability that primarily affects the ability to read and spell, despite normal...
• DysmenorrheaPainful menstrual cramps of uterine origin, occurring before or during menstruation. Primary dysmenorrhea is...
• DysmorphiaA deviation from the typical form or structure of a body part or organ, often present at birth. This...
• DysmorphogenesisThe process of abnormal development of form or structure during embryogenesis, leading to congenital...
• DysostosisA disorder characterized by abnormal ossification or defective formation of bone, often affecting specific...
• DysphagiaDifficulty in swallowing, which can involve problems with the oral, pharyngeal, or esophageal phases of the...
• DysphasiaA partial impairment in the ability to produce or comprehend spoken language, resulting from damage to the...
• DysplasiaAbnormal development or maturation of cells, a tissue or an organ, recognised on morphological examination by...
• DyspneaThe subjective sensation of difficult or labored breathing, often described as shortness of breath. This...
• Dystectic reactionA reversible, isobaric transformation in which a solid compound melts to a liquid of exactly the same...
• DystoniaA neurological movement disorder characterized by sustained or intermittent muscle contractions, leading to...
• Dystonic reactionA reversible dissolution process, at constant temperature and pressure, in a system of at least three...

730 of 13,676 terms in Chemistry terminology (MLC-0109). Request the full dataset.